“We are talking about an enabling new technology applied to an industry that has been around since the dawn of the industrial revolution,” says Michael Fuller, CEO of Conflux, a company using additive manufacturing to disrupt the heat exchanger market of 16, $6 billion.
According to Fuller, heat exchangers have been “on a divergent innovation curve for some time.” Over the past fifteen years, microtube technology, “essentially a hypodermic needle multiplied by tens of thousands” with very thin walls and assembled into large arrays to build “very powerful heat transfer devices”. But the microtube method has its limitations, especially the need for straight lines and the difficulty of automating the assembly process, which leads to high costs. In aerospace and motorsport, where cost sensitivity may be lower, “they are the benchmark.”
When placed face-to-face in “Formula 1-style boundary conditions for the charge air cooler” versus microtube technology, Conflux’s AM solution held its own; in fact, each technology “achieved the maximum heat transfer possible”. The results? “About 100% efficiency, meaning the hot air exit is about the same temperature as the coolant inlet”, a better result would be “a physical impossibility”. While efficiency was optimal for both the Conflux AM and microtube technology, the former required “30% less flow restriction or pressure drop across both fluid domains.” Additionally, the Conflux heat exchanger was 30% lighter when there was no coolant in the unit, 40% lighter when filled, and achieved a 15% volume reduction . These impressive statistics also come with “reasonable information to believe that we are definitely in a comparable cost position.”
Essentially, heat must enter or leave a system. “You have three legs of a stool. One of them being heat transfer, the other being pressure drop, and the third being weight,” says Fuller. Disappointing, but expected, “the FA does not allow us to break the rules of physics”. Any given amount of heat transfer requires a known amount of area. The larger the surface, the greater the pressure drop, “this gives more restriction to flow”. AM allows “three-dimensional surface geometries and tries to extract more heat transfer per unit square area”.
And with such gains, it’s perhaps reasonable to agree with Fuller’s proclamation, “we’re absolutely in the business of energy efficiency.”
The way to additive manufacturing
Fuller has a strong background in motorsport, including Formula 1, the World Rally Championship and Le Mans – “it’s super magical.” He worked with the Ford World Rally Team, BMW, Cytec and concluded this phase of his career with Mercedes F1.
Microwaves, penicillin and corn flakes – some of the most revolutionary breakthroughs in science or technology are the result of chance accidents. In Fuller’s case, the accident was far from figurative. A broken leg and ankle prevented him from traveling. “I was locked up for ten weeks, then I designed an AM-specific heat exchanger.” Working in high-level motorsport gave me early exposure to additive manufacturing and “lots of heat transfer issues to solve over my career.” With the germ of an idea, he took a “deep dive into building a business.”
The light bulb moment was “around the fundamental opportunity the FA presented”. The performance of a heat exchanger is “strongly geometry dependent”. Although additive manufacturing gives you greater design freedom, there are still limitations, but these are “new limitations…so there are new opportunities”. The designs that Fuller created had challenges, how to build and also how to model – quietly, as the CEO puts it, “it was pretty critical whether we could build some of these structures, some of the designs that I had. 3D modeling them was another thing that hadn’t really been done either.
Big projects are one thing, but what about bringing them to market? A business model is essential.
“We’ve done so far, we’ve done everything we said we would do, but not when we said we would,” Fuller says dryly. Conflux has a three-phase plan, first, “prove the technology”. To support the costs of hiring a team to do such product development, Conflux launched a services business model – quite simple.
While the first phase was underway, the pandemic arrived, ending the business travel needed to generate customers from North America, Europe and Asia. “We weren’t able to meet customers in person, which made it very difficult to continue this service business model. It turns out that people buy from people.
Faced with travel restrictions, Conflux pivoted or rather made “an accelerated race towards phase two of the business, which is more configurable products”. This brought Conflux to a Series A funding round, announced in October 2021. The results are that a series of product families were soft-launched during Formnext 2021 – with a broader launch throughout 2022.
How did AM Ventures get involved?
In 2016, AM Ventures researched the company when it was in its early stages, “at which point we weren’t mature enough to have our ducks in a row to raise seed capital.” Twelve months later, having started the business and with enough “rudimentary technology” to demonstrate the potential, Conflux closed a seed round with AM Ventures in July 2017.
For Fuller, having “the patient’s smart money” in the room is essential. “We needed investors who understood the challenges ahead of us even better than we did.” AM Ventures not only provides this smart money, but can also communicate at the board level with investors in subsequent funding rounds in a way that other venture capitalists might struggle with.
“Reducing energy consumption and increasing efficiency will be key to tackling climate change,” says Philip Schultheiss, senior partner at AM Ventures, which backs Conflux. “Michael and his team are designing the next generation of heat exchangers using additive manufacturing to tackle this challenging task. Their unique know-how in heat transfer and AM, combined with their excellent team spirit , convinced us that Conflux would be a great addition to our portfolio,” the VC adds.
Customers tend to have two “ingredients”, a curiosity about additive manufacturing and a heat transfer problem. As conversations with customers progressed from R&D to sourcing, the focus of the discussion shifted, for higher volume orders “They don’t care about the standard form, they have just the inputs and outputs where they want them as long as the performance is there. And the price is right.”
These customers come from all over the world and typically belong to one of six industry sectors: aerospace (including space), defense, automotive (general, premium and motorsport), industrial, microelectronics and energy. Given the stature of some clients, the names will be familiar to anyone with a passing interest in the respective sectors.
The industrialization of additive manufacturing
Conflux uses laser powder bed fusion to 3D print metal. “Other technologies aren’t really suitable for the type of heat exchangers we’re creating,” he says.
A considerable amount of R&D has gone into making Conflux designs work well: “You can’t build with a standard machine. It’s not plug-and-play,” says Fuller, “We develop parameters for every design we create. Fuller says his team of scientists and engineers means “our ability to solve the right technical problems is second to none.”
But a serious challenge remains: the current price of additive manufacturing systems dominates any discussion of costs. Conflux has achieved throughput gains through its technical expertise, but Fuller believes that the price of the machine is “the main obstacle to the industrialization of [AM] production.” Market forces can still solve this challenge, “Chinese machine makers will come in with much lower prices and if they can get their good quality, which I’m sure they will over time, then it will amaze the Germans and the British to produce cheaper machines and sell cheaper machines,” predicts Fuller. And what is Fuller’s position on the seemingly enduring subject of industrialization? Higher productivity and lower system costs are essential if industrialization is to take place.
What’s next for Conflux? Fullers says, “We’ve moved from application development to a commercial lab-type business, where we do a lot of service, design and prototyping, and low-volume mass production, to increase our production capacity. We will have a new production-oriented platform in the EOS M300. The audits for AS 9100 certification are approaching, in addition to the current ISO 9001 certification. Additionally, a product digitization roadmap is progressing.
“Looking ahead, we see Conflux heat exchangers will be widely adopted in general industry, aerospace and automotive, wherever the highest performance and excellent efficiency are required,” says Philip Schultheiss of AM Ventures.
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Featured image shows 3D printed heat exchangers. Photo via Conflux.